winedbg: Ensure thread->name is null-terminated.

programs/winedbg/tgt_active.c

@@ -257,9 +257,12 @@ static DWORD dbg_handle_exception(const EXCEPTION_RECORD* rec, BOOL first_chance
             dbg_printf("Thread ID=%04lx not in our list of threads -> can't rename\n", pThreadName->dwThreadID);
             return DBG_CONTINUE;
         }
-        if (dbg_read_memory(pThreadName->szName, pThread->name, 9))
-            dbg_printf("Thread ID=%04lx renamed using MS VC6 extension (name==\"%.9s\")\n",
+        if (dbg_read_memory(pThreadName->szName, pThread->name, sizeof(pThread->name)))
+        {
+            pThread->name[sizeof(pThread->name) - 1] = '\0';
+            dbg_printf("Thread ID=%04lx renamed using MSVC extension (name==\"%s\")\n",
                        pThread->tid, pThread->name);
+        }
         return DBG_CONTINUE;
     case EXCEPTION_INVALID_HANDLE:
         return DBG_CONTINUE;